Question

During inhalation the diaphragm moves
(a) upwards
(b) downwards
(c) towards left
(d) towards right

Answer 1

(b) downwards
During inhalation, the external intercostal muscles contract and lift ribs outward, while the diaphragm becomes flat and moves down thereby increasing the volume of the thoracic cavity.

During exhalation, the external intercostal muscles return the diaphragm and ribs to their normal thoracic volume. Ribs move down and inwards while the diaphragm moves up.